Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Development of large aperture projection scatterometry for catalyst loading evaluation in proton exchange membrane fuel cells



Michael T. Stocker, Bryan M. Barnes, Martin Y. Sohn, Eric S. Stanfield, Richard M. Silver


Widespread commercialization of proton exchange membrane fuel cells remains curbed by various manufacturing and infrastructure challenges. One such technical barrier identified by the U. S. Department of Energy is the need for high-speed, in-line process control of platinum-based catalyst layers in the membrane electrode assembly of the fuel cell. Using multiple reflectivity-based optical methods, such as optical scatterometry and large aperture projection scatterometry, we demonstrate in-line-capable catalyst loading measurements of carbon-supported Pt nanoparticle and Pt-alloy nanostructured thin film catalyst coated membranes. Large aperture projection scatterometry is a new high-throughput approach developed at the National Institute of Standards and Technology specifically for fuel cell manufacturing metrology. Angle- and wavelength-resolved measurements of these fuel cell soft goods validate the ability of reflectivity-based measurements to produce industrially relevant sensitivities to changes in Pt and Pt-alloy loading. The successful application of these optical methods to fuel cell manufacturing metrology directly addresses the shortage of high-throughput process control approaches needed to facilitate performance improvements and manufacturing cost-reductions required to make fuel cells commercially viable.
Journal of Power Sources


Proton-exchange membrane, catalyst coated membrane, process control, Pt loading, optical inspection, fuel cell manufacturing


Stocker, M. , Barnes, B. , Sohn, M. , Stanfield, E. and Silver, R. (2017), Development of large aperture projection scatterometry for catalyst loading evaluation in proton exchange membrane fuel cells, Journal of Power Sources, [online], (Accessed May 30, 2024)


If you have any questions about this publication or are having problems accessing it, please contact

Created August 12, 2017, Updated November 10, 2018